//
// (C) Copyright 2009 Irantha Suwandarathna (irantha@gmail.com)
// All rights reserved.
//

/* Copyright (c) 2001-2008, The HSQL Development Group
 * All rights reserved.
 *
 * Redistribution and use _in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions _in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer _in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of the HSQL Development Group nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


using System;
using System.Text;
using EffiProzDB.RowIO;
using EffiProzDB.Lib;


namespace EffiProzDB.ScriptIO{

/**
 * Handles all scripting and logging operations. A script consists of two blocks:<p>
 *
 * DDL: SQL statements for table and user definitions
 * DATA: INSERT statements for memory tables
 *
 * This happens as part of the CHECKPOINT and SHUTDOWN COMPACT
 * process. In this case, the
 * DATA block contains the CACHED table data as well.<p>
 *
 * A related use for this class is for saving a current snapshot of the
 * database data to a user-defined file with the SCRIPT command
 *
 * A log consists of SQL statements of different types. Each statement is
 * encoded as ASCII and saved.
 *
 *
 * @author fredt@users
 * @version 1.8.0
 * @since 1.7.2
 */
public class ScriptWriterText : ScriptWriterBase {

    RowOutputTextLog rowOut;

    // todo - perhaps move this global into a lib utility class
    public static  byte[] BYTES_LINE_SEP;

    static ScriptWriterText(){
        string sLineSep = Environment.GetEnvironmentVariable("line.separator");
        if (sLineSep == null)
            sLineSep = Environment.NewLine;

        BYTES_LINE_SEP = Encoding.UTF8.GetBytes(sLineSep);
    }

    static  byte[] BYTES_COMMIT       = Encoding.UTF8.GetBytes("COMMIT");
    static byte[] BYTES_INSERT_INTO = Encoding.UTF8.GetBytes("INSERT INTO ");
    static byte[] BYTES_VALUES = Encoding.UTF8.GetBytes(" VALUES(");
    static byte[] BYTES_TERM = Encoding.UTF8.GetBytes(")");
    static byte[] BYTES_DELETE_FROM = Encoding.UTF8.GetBytes("DELETE FROM ");
    static byte[] BYTES_WHERE = Encoding.UTF8.GetBytes(" WHERE ");
    static byte[] BYTES_SEQUENCE = Encoding.UTF8.GetBytes("ALTER SEQUENCE ");
    static byte[] BYTES_SEQUENCE_MID = Encoding.UTF8.GetBytes(" RESTART WITH ");
    static byte[] BYTES_C_ID_INIT = Encoding.UTF8.GetBytes("/*C");
    static byte[] BYTES_C_ID_TERM = Encoding.UTF8.GetBytes("*/");
    static byte[] BYTES_SCHEMA = Encoding.UTF8.GetBytes("SET SCHEMA ");

    ScriptWriterText() {}

    public ScriptWriterText(Database db, string file,
                            bool includeCachedData, bool newFile,
                            bool isDump)  :base(db, file, includeCachedData, newFile, isDump) {
        
    }

    protected override void initBuffers()
    {
        rowOut = new RowOutputTextLog();
    }

    protected override void writeDataTerm() { }

    protected override void addSessionId(Session session)
    {

        if (session == null) {
            return;
        }

        if (session != currentSession) {
            rowOut.write(BYTES_C_ID_INIT);
            rowOut.writeIntData(session.getId());
            rowOut.write(BYTES_C_ID_TERM);

            currentSession = session;
        }

        if (schemaToLog != session.loggedSchema) {
            writeSchemaStatement(schemaToLog);

            session.loggedSchema = schemaToLog;
        }
    }

    private void writeSchemaStatement(HsqlNameManager.HsqlName schema) {

        rowOut.write(BYTES_SCHEMA);
        rowOut.writeString(schema.statementName);
        rowOut.write(BYTES_LINE_SEP);
    }

    public override void writeLogStatement(Session session,
                                  string s)
                                     {

        schemaToLog = session.currentSchema;
        busyWriting = true;

        rowOut.reset();
        addSessionId(session);
        rowOut.writeString(s);
        rowOut.write(BYTES_LINE_SEP);
        fileStreamOut.Write(rowOut.getBuffer(), 0, rowOut.size());

        byteCount   += rowOut.size();
        needsSync   = true;
        busyWriting = false;

        if (forceSync || writeDelay == 0) {
            sync();
        }
    }

    public override void writeRow(Session session, Table table,
                            Object[] data) {

        busyWriting = true;

        rowOut.reset();
        ((RowOutputTextLog) rowOut).setMode(RowOutputTextLog.MODE_INSERT);
        addSessionId(session);
        rowOut.write(BYTES_INSERT_INTO);
        rowOut.writeString(table.getName().statementName);
        rowOut.write(BYTES_VALUES);
        rowOut.writeData(data, table);
        rowOut.write(BYTES_TERM);
        rowOut.write(BYTES_LINE_SEP);
        fileStreamOut.Write(rowOut.getBuffer(), 0, rowOut.size());

        byteCount   += rowOut.size();
        needsSync   |= session.isAutoCommit();
        busyWriting = false;

        if (forceSync || writeDelay == 0) {
            sync();
        }
    }

    protected override void writeTableInit(Table t)
    {

        if (t.isEmpty(currentSession)) {
            return;
        }

        if (schemaToLog == currentSession.loggedSchema) {
            return;
        }

        rowOut.reset();
        writeSchemaStatement(t.getName().schema);
        fileStreamOut.Write(rowOut.getBuffer(), 0, rowOut.size());

        currentSession.loggedSchema = schemaToLog;
    }

    public override void writeInsertStatement(Session session, Table table,
                                     Object[] data)
                                      {

        schemaToLog = table.getName().schema;

        writeRow(session, table, data);
    }

    public override void writeDeleteStatement(Session session, Table table,
                                     Object[] data)
                                       {

        schemaToLog = table.getName().schema;
        busyWriting = true;

        rowOut.reset();
        ((RowOutputTextLog) rowOut).setMode(RowOutputTextLog.MODE_DELETE);
        addSessionId(session);
        rowOut.write(BYTES_DELETE_FROM);
        rowOut.writeString(table.getName().statementName);
        rowOut.write(BYTES_WHERE);
        rowOut.writeData(table.getColumnCount(), table.getColumnTypes(),
                         data, table.getColumnList(), table.getPrimaryKey());
        rowOut.write(BYTES_LINE_SEP);
        fileStreamOut.Write(rowOut.getBuffer(), 0, rowOut.size());

        byteCount   += rowOut.size();
        needsSync   |= session.isAutoCommit();
        busyWriting = false;

        if (forceSync || writeDelay == 0) {
            sync();
        }
    }

    public override void writeSequenceStatement(Session session,
                                       NumberSequence seq)
                                        {

        schemaToLog = seq.getName().schema;
        busyWriting = true;

        rowOut.reset();
        addSessionId(session);
        rowOut.write(BYTES_SEQUENCE);
        rowOut.writeString(seq.getName().statementName);
        rowOut.write(BYTES_SEQUENCE_MID);
        rowOut.writeLongData(seq.peek());
        rowOut.write(BYTES_LINE_SEP);
        fileStreamOut.Write(rowOut.getBuffer(), 0, rowOut.size());

        byteCount   += rowOut.size();
        needsSync   = true;
        busyWriting = false;

        if (forceSync || writeDelay == 0) {
            sync();
        }
    }

    public override void writeCommitStatement(Session session)
    {

        busyWriting = true;

        rowOut.reset();
        addSessionId(session);
        rowOut.write(BYTES_COMMIT);
        rowOut.write(BYTES_LINE_SEP);
        fileStreamOut.Write(rowOut.getBuffer(), 0, rowOut.size());

        byteCount   += rowOut.size();
        needsSync   = true;
        busyWriting = false;

        if (forceSync || writeDelay == 0) {
            sync();
        }
    }

    protected void finalize() {
        sync();
    }
}
}


